CASELAW-EPO - reviews of EPO Boards of Appeal decisions

T 196/22 - 6 differences with the CPA – No synergy

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The patent relates to a battery driven lawn mower.

Brief outline of the case

The patent was maintained according to AR 6.

Both opponents appealed.

The board held that claim 1 of AR 6 was lacking IS over D2=DE 195 28 167 with common general knowledge.

AR 11a, 12, 12a and 14a were not admitted under Art 12(4) RPBA. AR 16 was not admitted under Art 13(2) RPBA.

The patent was thus revoked.

The case is interesting in that the board found that all the differences with respect to the CPA did not involve any synergy.

The differences with respect to the CPA

The subject matter of claim 1 differs from D2 in the features B, D, F, G and H:

– The electric motor is of the electronically commutated DC type (feature B).

– The battery compartment has an openable battery cover (feature D).

– The battery unit comprises a lithium-ion (LiIon) battery (feature F)

– The control system comprises a speed control system, including a feedback system to drive the electronically commutated motor at a constant speed (Feature G)

– The control system comprises a battery unit condition monitoring system comprising a voltage-monitoring system and/or a temperature-monitoring system (Feature H, first part),

– The battery-unit monitoring circuitry is incorporated together with the control system electronics (Feature H, second part).

The OD’s point of view

The OD considered IS starting from D2 as CPA in combination with the skilled person’s general knowledge and various documents. The OD came to the conclusion that the subject matter of claim 1 involved an IS, in particular because the last claim feature, second part of feature H, was considered not to be obvious.  

The proprietor’s point of view

The proprietor contended that the differing claim features, ie. B,D,F,G and H, are clearly interrelated and must therefore form a combination invention in which the differing features must be considered together when assessing IS.

At the OP before the board, the proprietor seemed to argue that synergy between features B, D, F, G and H lay therein that these constituted a chain of linked improvements with one contingent on the other. Thus, when starting from the problem of weight, a first step for the patented invention was to use an ECDC motor.

Though this motor is light-weight, it would require a more powerful battery. Merely inserting a bigger battery of the same type would however negate any weight saved by the lighter motor.

That could be countered by a Li Ion battery with higher energy density. A Li-Ion battery however suffers from overheating, which could then be avoided by monitoring its temperature.

All these changes would form a chain of linked improvements, a sequence of steps, that achieve the over-arching objective of a light-weight, efficient lawn mower and should therefore be considered together.

The board’s decision

For the board, a mere interrelation between features, such as their forming part of the same apparatus, is insufficient for their being considered together when assessing IS, however unusual it may be for there to be so many differing features.

The board referred to established jurisprudence, cf. Case Law of the Boards of Appeal, 10th edition, 2022 (CLBA) I.D.9.3.1 and to T1054/05, reasons 4.5. The existence of a combination invention requires that features or groups of features must show a combinative effect beyond the sum of their individual effects, in other words they must interact synergistically.

According to the published patent specification, the technical effects/problems solved of the various differing features are as follows:

– An electronically commutated direct current motor (ECDC) provides for an efficient motor and is low in weight due to its not being commutated using brushes and having smaller armature windings.

– The patent is silent as to any effect of a battery cover, it is merely said to be preferable, at most it seems implicit that a cover will protect the battery from ingress of unwanted substances such as dirt.

– A Li-Ion battery has a high energy density, and is thus low in weight for the amount of energy it can store, as well as enabling rapid charging without memory effects or self-discharge.

– The patent attributes no particular advantage to the feature of a speed control system with feedback to drive the motor at a constant speed. At most it is merely described as advantageous.

– Likewise, the patent explains no particular advantage to monitoring the battery voltage/temperature as such. The effect of this feature would therefore appear to be no more than providing monitoring information. At most, only when used in conjunction with a switch means for interrupting the charging or discharging process, which has not been claimed, would there appear to be an effect of enhancing charging/discharging safety.

– Finally, the idea of incorporating battery monitoring circuitry with control system electronics, whatever part of the monitoring circuitry might be incorporated with the control system, seems to be presented in the patent as saving costs, presumably by avoiding some hardware duplication, be this of a circuit board, housing or whatever else.

On the face of it, all these effects and advantages appear to be independent of each other, and thus do not prove that the differing features interact synergistically.

That there might exist a sequence of steps as argued during OP, does not demonstrate to the board that their total effect is more than the sum of their individual effects, and the board is thus unable to see therein any synergy. The set of features can be considered an aggregation and obviousness of each individual step can be considered in isolation. Only if at least one of those steps can be seen to be non-obvious can IS be concluded. The number of steps or the number of documents cited plays no role.

As far as the second part of feature H is concerned, which was considered inventive by the OD the board noted that it requires no more than for some part of the battery monitoring circuitry to be combined with the apparatus’s control system electronics.

It is common ground that the technical effect of this feature is one of saving costs. Starting from D2, the objective technical problem associated with this feature can be expressed as how to implement the control system of D2’s lawn-care apparatus economically.

As already established, the skilled person would modify D2 to introduce the features of a Li Ion battery with battery condition monitoring circuitry per se as a matter of obviousness, from D15=DE 11 2005 001 203 T5 = Publication in German of PCT application WO 2005/117232. In the board’s view, faced with the objective technical problem (economic implementation), the skilled person would likewise incorporate battery monitoring circuitry into D2’s control arrangement as a matter of obviousness from the teaching of D15.

Claim 1 as maintained was thus lacking IS.


The present decision does reminds us that a lot of differences with the CPA does not necessarily imply IS. There is no IS if all those features merely represent an aggregation of features. Optional/advantageous features can also not help IS in case of a mere aggregation.

On the procedure

D2=DE 195 28 167 was not mentioned on the ISR established by the EPO.

Neither D15=DE 11 2005 001 203 T5, nor WO 2005/117232 were mentioned on the ISR established by the EPO.

Cl1 as granted lack IS over D2=DE 195 28 167 + D26 representing common general knowledge. The same applied to AR1-3.

AR4 was not allowable under R 80 and Art 84 as not being concise, since claim 1 as granted was divided in two independent claims.  

AR5 lacked IS over D2 + CGK or D2+D18=GB 2 110 432, first X in the ISR, or D2+D4=DE 196 31 555 not mentioned in the ISR.

Lots of important documents were thus not found in the initial search.

As far as AR6 might be concerned, one can suppose that the OD gave in to the proprietor by attrition.

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